The present invention relates to recoil mechanisms. More particularly, the present invention relates to a system and method for actively controlling a recoil mechanism.
Energy absorbing devices, such as, for example, recoil devices, are commonly used in weapons to dissipate the recoil energy created during the firing of a round. A weapon creates recoil energy when a propellant contained within the round is ignited. The burning of the propellant generates high pressure gases between a projectile and a recoiling portion of the weapon. The high pressure gasses exert a force on both the projectile and the recoiling portion of the weapon, which causes the recoiling portion of the weapon to move in the opposite direction of the projectile.
An energy absorbing device may be connected between the recoiling portion and a support carriage to dissipate the recoil energy as the recoiling portion travels through a certain recoil distance. The energy absorbing device may exert a force that counters the movement of the recoiling portion to thereby dissipate the recoil energy. Ideally, the energy absorbing device will exert a substantially constant force to oppose the movement of the recoiling portion. An ideal plot of the countering force as a function of time will have a generally trapezoidal shape, i.e. the the majority of the recoil travel, and the countering force will quickly subside at the end of the recoil travel. This force profile will maximize the amount of energy dissipated while minimizing the magnitude of the force transferred to the supporting carriage of the weapon. Accordingly, the weight of the supporting carriage, and thus the overall weight of the weapon, may be minimized.
An energy absorbing device may include a hydraulic system that absorbs the recoil energy of the fired round. The hydraulic system may include a piston and cylinder combination that absorbs the recoil energy by throttling hydraulic fluid from a high pressure chamber through one or more orifices to a low pressure chamber. The force required to throttle the fluid through the orifices counters the movement of the piston. The magnitude of the countering force is dependent, in part, on the size of the orifices. The orifices are typically sized to ensure that the recoil energy is dissipated as the recoiling portion travels through a predetermined distance.
In a hydraulic recoil system, the amount and rate of recoil energy dissipation is dependent upon many factors. For example, the dissipation rate is dependent upon the velocity of the recoil portion of the weapon, the properties of the hydraulic fluid, and the sizes of the piston and corresponding orifices. However, the recoil energy generated by a fired round is also dependent upon many factors, including, for example, the type of round fired, the propellant charge in the round, the climatic conditions, the wear on the weapon, and the position of the weapon. Typically, hydraulic recoil devices are designed to dissipate the greatest expected amount of recoil energy, such as would be experienced when firing a round of the greatest impulse ammunition for the particular weapon.
A hydraulic recoil device may be designed to generate a trapezoidal force profile when subjected to one amount of recoil energy. However, the hydraulic recoil device may behave differently when subjected to a lesser, or greater, amount of recoil energy. When subjected to an unexpected amount of recoil energy, a hydraulic recoil system with a fixed configuration may not provide a trapezoidal shaped force profile.
It would be desirable to provide a recoil device capable of responding to varying conditions, such as differing amounts of recoil energy, when the weapon is in the field. Various control schemes have been proposed and tried with varying degrees of success. For example, a hydraulic recoil device may be equipped with a mechanical servo valve that controls the size of the orifices between the high and low pressure chambers. This mechanical servo valve may be actively controlled to vary the size of the orifices based on sensed operating conditions of the weapon, such as gun dynamics and ambient conditions. This type of active control device may allow the countering force of the recoil mechanism to be tailored to suit the particular operating conditions.
However, to achieve an ideal force profile, the active control system should quickly respond to changes in either gun dynamics or ambient conditions. Unfortunately, the mechanical servo valves described above may not be responsive enough to changing operating conditions. This may lead to erratic performance of
The present invention is directed to a recoil mechanism that provides active control over the magnitude and rate of energy dissipation to quickly respond to changing conditions and to generate an ideal countering force profile.
Accordingly, the present invention is directed to a recoil mechanism that compensates for one or more of the limitations and disadvantages of prior art recoil mechanisms. The advantages and purposes of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purposes of the invention will be realized and attained by the elements and combinations particularly pointed out in the appended claims.
In accordance with one aspect, the present invention is directed to a recoil mechanism for a weapon. The recoil mechanism includes a housing that contains a hydraulic fluid and has an inner wall defining a first chamber and a second chamber within the housing. The inner wall has at least one orifice that connects the first and second chambers. A piston is slidably disposed within the first chamber of the housing. A shuttle valve is slidably disposed within the first chamber of the housing and has at least one orifice configured to align with the at least one orifice in the inner wall of the housing to define a fluid passageway between the first and second chambers. A shuttle valve control is operable to generate a magnetic field in response to an applied current to control the movement of the shuttle valve to thereby control the size of the fluid passageway between the first and second
In accordance with another aspect, the present invention is directed to a recoil mechanism for a weapon that includes a housing containing a hydraulic fluid and having an inner wall defining a first chamber and a second chamber within the housing. The inner wall has at least one orifice that connects the first and second chambers. A piston is slidably disposed within the first chamber of the housing. A shuttle valve is slidably disposed within the first chamber of the housing and has at least one orifice configured to align with the at least one orifice in the inner wall of the housing to define a fluid passageway between the first and second chambers. A control means generates a magnetic field to control the movement of the shuttle valve in response to an applied current to thereby control the size of the fluid passageway between the first and second chambers.
According to another aspect, the present invention is directed to a weapon that includes a support carriage and a barrel assembly that is slidably disposed on the support carriage. A recoil device is disposed between the support carriage and the barrel assembly. The recoil device includes a housing that contains a hydraulic fluid and has an inner wall defining a first chamber and a second chamber within the housing. The inner wall has at least one orifice that connects the first and second chambers. A piston is slidably disposed within the first chamber of the housing. A shuttle valve is slidably disposed within the first chamber of the housing and has at least one orifice configured to align with the at least one orifice in the inner wall of the housing to define a fluid passageway between the first and second chambers. A shuttle valve control is operable to generate a magnetic field in response to an applied current to govern the movement of the shuttle valve and thereby control the size of the fluid passageway between the first and second chambers.
In yet another aspect, the present invention is directed to a method of absorbing a recoil momentum generated by a weapon. A fluid pressurized by the momentum of the piston is throttled through a fluid passageway connecting the first chamber of the housing with a second chamber in the housing to exert a fluid force against the motion of the piston. An operating condition of the weapon is sensed. A magnetic field is generated to control the motion of a shuttle valve based on the sensed operating condition. The motion of the shuttle valve varies the size of the fluid passageway between the first and second chambers to provide control over the magnitude of the fluid force exerted on the piston.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.